Lord Krishna has come to the last pair of topics, purusha and prakriti.  Purusha and prakriti are two basic principles that existed even before the creation of the world, and this mixture of purusha and prakriti is called God.  The common features of purusha and prakriti are both are anädi and both of them can’t be the cause of creation alone.

Uncommon features or difference between Purusha and Prakriti are:

1. Purusha is chethanam and Prakriti is achethanam.
2. Purusha is nirvikāram.  Prakrithi is savikāram.
3. Purusha nirgunam; Maya is sagunam.
4. Purusha sathyam; Prakriti is mithyam.

Everything is prakriti and purusha is available behind the body mind complex and available as the witness.  Whatever is experienced or witnessed is prakriti or the object of experience.  The body mind complex falls under prakriti or the object of experience.  The body mind complex is used as a medium to experience and witness and as a result often mistaken for Purusha or I.  The body mind complex used as an instrument, appears as subject.   World is prakriti, mind is prakriti.  I am different than the world, mind and prakriti.  Illumining the body mind is not the activity of Purusha, but the body mind illumined by the very presence of purusha.    This is similar to sun.  Sun does not illumine the objects, the objects get illumined by the very presence of the sun.  Even the blank condition of the mind is also witnessed by the consciousness.  Transference of body mind complex attributes to I, the consciousness and witness, causes samsara.  This is similar to transferring the problems of a character in a movie to me, the audience.     

Verse 23

The supreme purusha in this body is said to be the proximate witness, the supporter, the sustainer, the experiencer, the great Lord and the supreme Self.

Krishna says purusha is in the form of witness everywhere.  The nature of this purusha is different than the prakriti. Lord Krishna gives more features of purusha:

1. Paraha:  Free from all limitations; The consciousness not only within the body, it is also extends beyond the body.  Eventually we must realize that we are inside the consciousness.  This is similar to space.  Space is inside the room, outside the room; but really the room is in space.
2. Upadhrishta:  The intimate witness of everything happening inside you.  Purusha pervades every cell of our bodies. 
3. Anumandhacha:  Purusha blesses inert body and mind and because of its blessing alone body is what it is. 
4. Bartha:  Purusha lends existence to everything in creation.
5. Boktha:  Purusha is experiencer from the standpoint of an ignorant person.  Seeming boktha, as though suffering from attributes.
6. Maheswaraha:  Purusha is ever free.  For a wise person, consciousness is a free entity.  Body and mind are bound by prakriti, but purusha is not. 

I am called jivatma when I take the attributes of prakriti, but when I take the attributes and understand that they don’t belong to me but to prakriti, then I am paramatma.  

Verse 24

He who thus knows purusha and prakriti along with the gunas, is not born again, in whatever manner he lives. This clear knowledge about prakriti and purusha will give a person great relief from samsara.  The initial knowledge is I am a mixture of purusha and  prakriti. I also know there are many physical attributes and subtle, internal attributes.   But these attributes belong to prakriti.   For all day-to-day activities, we have to identify with prakriti. But understand that the whole life is a series of role playing. But when role playing is taken seriously, it results in samsara.  A Jñāni who understands this, he will not have a punar jenma or re-birth.